Hydroponic turfgrass athletic field and landscape apparatus

ABSTRACT

The present invention discloses a hydroponic field irrigation system comprising a field module for growing turfgrass. The field module comprises an energy absorbing mechanism comprising a horizontal spring layer and a growth medium comprising a steel grid layer, wherein the horizontal spring layer absorbs vertical forces exerted by external loads, and the steel grid layer is positioned on top of the horizontal spring layer for holding a plurality of turf sods. The hydroponic field irrigation system further comprises a used water tank for receiving water from the field module, an ultra-violet (UV) unit for disinfecting the water received from the used water tank, a water quality management unit for adjusting quality of the water received from the ultra-violet (UV) unit, a geothermal unit for conditioning temperature of water received from the water quality management unit and plurality of solenoid valves for pumping water into and out of the field module.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

This patent application is a divisional of U.S. patent application Ser.No. 16/274,583 filed Feb. 13, 2019. This patent application is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to hydroponic turfgrass irrigation, andmore particularly to a hydroponic field irrigation system designed togrow turfgrass, or to simulate natural turf fields.

BACKGROUND OF THE INVENTION

Water scarcity is the lack of sufficient available water resources tomeet the demands of water usage within a region. Water use has beengrowing globally at more than twice the rate of population increase inthe last century, and an increasing number of regions are reaching thelimit at which water services can be sustainably delivered, especiallyin arid regions. Water scarcity can be a result of two mechanisms;physical water scarcity and economic water scarcity, where physicalwater scarcity is a result of inadequate natural water resources tosupply a region's demand due to physical shortage, or economic waterscarcity is lack of access due to lack of adequate infrastructure toensure a regular supply. The reduction of water scarcity is a goal ofmany countries, and the importance of good water management of thesufficient available water resources has been recognised globally.

For this reason, there is an increasing pressure to develop sustainablewater management practices. Particularly, the increasing consumption inturf and landscape areas, the dependence on potable water, inefficientirrigation practices and the relatively low use of recycled or greywaterfor irrigation are some of the issues that need to be addressed.

There are many examples of situations in which water used to irrigateturfgrass fields has been inefficient and waste through poor watermanagement practices. For example, during periods of low precipitationand high temperatures, fields are required to be irrigated four to seventimes every week. More specifically, during the 2010 FIFA World Cup thattook place in South Africa, 26,417 US gallons of water a day wereutilised, which is the equivalent of 100,000 litres. On the other hand,a typical golf course requires 100,000 to 1,000,000 gallons per week tomaintain healthy vegetation in the summer period.

This is notably a larger problem in regions with warmer climates, asstudies have reported that direct evaporation from sprinklers canaccount for a 50 percent or greater loss of water in a desert climate.Overall, it's the climate or environment that is the primaryconsideration for grass selection. The region's average low temperatureis often used to determine grasses that are appropriate for the area.Moreover, different environmental factors such as solar radiation,temperature, relative humidity, and wind movement, all result in anincrease in evaporation losses from irrigation, in addition to operatingpressures, and nozzle diameter.

As a result of the above, importance has been placed upon goodirrigation practice and consequently improving turfgrass technology.Artificial turf fields have been developed to reduce managementrequirements as well as sustainable water usage. With recentadvancements in athletic fields and landscape apparatus, turfgrass is acommon artificial grass solution for outdoor athletic fields. Turfgrassis usually a high-quality grass made of innovative materials that willprovide a quality playing surface, which is appreciated by sportsparticipants and produces a pleasing appearance to spectators. There isa growing emphasis on prevention of water wastage and nutrient solutionrecycling as it is widely known turfgrass technology is an importantfield within turfgrass athletic field and landscape apparatus.

Previously, artificial turf-like products have been developed thatprovide a surface resembling grass, specifically products withcharacteristics equivalent to those displayed by real turf intended forathletic purposes. Other developments include a drainable turf assemblyand a rapidly draining artificial turf assembly for a support surface,such as a playing field. Additionally, other developers and researchersdesigned a subsurface mat that includes a perforated tube, a web made ofa first capillary textile and a casing made of a second capillarytextile to irrigate fields and landscape, to prevent irrigation waterdrift due to wind and heat.

Although artificial turf fields have been a realistic alternative,concerns regarding health and environmental issues have recentlyincreased. High levels of lead have been discovered in a number of“in-use” artificial turf fields of varying ages and types of materials.The lead is mixed within the fibers as a lead chromate paint for brightcoloration of the surface, with the surfaces degrading over time due tooveruse and weathering. As a result, lead can be released from the olderturf material by just wiping the surface with synthetic sweat orextracting from the turf fibers using a synthesis digestive system. Insome cases, the amount on wipe exceeds residential guidelines for leadon floor surfaces, that is 40 μg/ft², and it is likely that continuedaging of the turf will result in even greater releases. Furthermore, theease of mobilization would enhance the probability of re-suspension oflead into the breathing zone of athletes and other users, especiallyyoung children. The infill rubber crumbles used in this type of fieldsrepresents a more complex issue where 24.7-44.2% of the lead in therubber granules was bio-accessible in the synthetic gastric fluid.

As a result of the above, turf fields have been developed to reducemanagement requirements, efficient nutrient recycling and sustainablewater usage. More recently, hydroponic technology has been introducedwhich comprises a soil-less plant growing technique. Hydroponictechnology is method using nutrient solutions such as chemicalfertiliser or manure in a water solvent to grow the plants as areplacement for soil. The roots of terrestrial plants are usually placedwithin the mineral solution to allow growth. Due to the technologicaladvancements within this industry, it has become a popular choice forturfgrass technology.

Moreover, in countries with a tropical desert climate the major limitingfactors in traditional agriculture production is the harsh climate andscarce water resources. Hydroponic technology provides a solution to theregions as it offers the ability to grow anywhere in much higher yieldswhile using a fraction of resources such as land and water. It allowsfarmers to grow their own crops at their own facility at any scale. In acontrolled system, without the need for soil, much less water isrequired to grow sustainable, year-round crops. For these reasons,efforts towards developments of hydroponics systems are designedspecifically for the desert climate to optimize production.

Accordingly, there exists a need for a hydroponic turf design, whichprovides a sustainable water supply and effectively reduces ecologicalimpact, whilst meeting the requirements of a specific purpose field suchas athletic fields.

SUMMARY OF THE INVENTION

Therefore it is an object of the present invention to develop ahydroponic turfgrass irrigation system, to grow turfgrass.

The present invention involves a field module for growing turfgrass, thefield module comprising an energy absorbing mechanism comprising ahorizontal spring layer and a growth medium comprising a steel gridlayer, wherein the horizontal spring layer absorbs vertical forcesexerted by external loads, and the steel grid layer is positioned on topof the horizontal spring layer for holding a plurality of turf sods.

In an embodiment of the present invention, the field module furthercomprises a 25 cm deep container made of fiberglass, galvanized steel orconcrete.

In an embodiment of the present invention, the horizontal spring layeris a perforated corrugated sheet made of galvanized steel.

In an embodiment of the present invention, spaces between the perforatedcorrugated sheet are filled with rockwool which acts as a growthsubstrate for the turfgrass.

In an embodiment of the present invention, a thickness of the horizontalspring layer is 3 to 4 mm.

In an embodiment of the present invention, the horizontal spring layeris capable of moving horizontally, thereby imitating natural resilienceof soil.

In an embodiment of the present invention, the field module furthercomprises a slidable sheet layer positioned below the horizontal springlayer for assisting the horizontal spring layer to move horizontally.

In an embodiment of the present invention, the slidable sheet layer ismade of galvanized steel.

In an embodiment of the present invention, the external loads compriseplayers, pedestrians or sporting equipment.

As a further aspect of the present invention, there is presented ahydroponic field irrigation system for growing turfgrass, the hydroponicfield irrigation system comprising a field module for growing theturfgrass, a used water tank for receiving water from the field module,an ultra-violet (UV) unit for disinfecting the water received from theused water tank, a water quality management unit for adjusting a qualityof the water received from the ultra-violet (UV) unit, a geothermal unitfor conditioning a temperature of the water received from the waterquality management unit and a plurality of solenoid valves for pumpingwater into and out of the field module.

In an embodiment of the present invention, the plurality of solenoidvalves comprise a first solenoid valve and a second solenoid valve.

In an embodiment of the present invention, the first solenoid valveallows fresh water into the field module and the second solenoid valveallows used water out from the field module.

In an embodiment of the present invention, the water quality managementunit sustains a pH level and electric conductivity level of the waterreceived from the ultra-violet (UV) unit.

In an embodiment of the present invention, the geothermal unit functionsbased on day or night or winter or summer cycles for conditioning atemperature of the water received from the water quality managementunit.

In an embodiment of the present invention, the field module comprises ahorizontal spring layer for absorbing vertical forces exerted byexternal loads, a steel grid layer positioned on top of the horizontalspring layer for holding a plurality of turf sods; and a slidable sheetlayer positioned below the horizontal spring layer for assisting thehorizontal spring layer to move horizontally.

In an embodiment of the present invention, the field module furthercomprises a 25 cm deep container made of fiberglass, galvanized steel orconcrete.

In an embodiment of the present invention, the horizontal spring layeris a perforated corrugated sheet made of galvanized steel.

In an embodiment of the present invention, spaces between the perforatedcorrugated sheet are filled with rockwool which acts as a growthsubstrate for the turfgrass.

In an embodiment of the present invention, a thickness of the horizontalspring layer is 3 to 4 mm.

In an embodiment of the present invention, the slidable sheet layer ismade of galvanized steel.

In an embodiment of the present invention, the external loads compriseplayers, pedestrians or sporting equipment.

As a further aspect of the present invention, there is presented aprocess for growing turfgrass using a hydroponic irrigation system, theprocess comprising the steps of pumping out used water from a fieldmodule, through a second solenoid valve, storing the used water in aused water tank, disinfecting the used water received from the usedwater tank using ultra-violet (UV) rays, adjusting a pH level andelectric conductivity level of the disinfected water, using a waterquality management unit, conditioning a temperature of the waterreceived from the water quality management unit, using a geothermalunit, pumping the conditioned water received from the geothermal unitinto the field module through a first solenoid valve, wherein the fieldmodule holds a plurality of turf sods on a grid layer positioned on topof the field module.

In an embodiment of the present invention, the field module furthercomprises a 25 cm deep container made of fiberglass, galvanized steel orconcrete.

In an embodiment of the present invention, the geothermal unit functionsbased on day or night or winter or summer cycles for conditioning atemperature of the water received from the water quality managementunit.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter that is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other aspects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 illustrates a field module in accordance with the presentinvention.

FIG. 2 depicts a hydroponic irrigation system in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The aspects of the hydroponic field module according to the presentinvention will be described in conjunction with FIGS. 1-2. In theDetailed Description, reference is made to the accompanying figures,which form a part hereof, and in which is shown by way of illustrationspecific embodiments in which the invention may be practiced. It is tobe understood that other embodiments may be utilized and logical changesmay be made without departing from the scope of the present invention.The following detailed description, therefore, is not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims.

The proposed solution aims at designing a field module, which isintended to grow turfgrass through a setup designed with an energyabsorbing mechanism and a growth medium. Hydroponic technology isutilized to circulate used water thereby improving water use efficiency,in addition to eliminating ground water contamination. This presentinvention also aims at improving water management systems, with anobjective to develop a soil-less athletic field module which mimicstypical grass fields.

More specifically, the present invention resolves the use of irrigatingfields with high pressure sprinkler irrigation systems and applyinggranular or liquid chemicals as a source of nutrients, which have beenthe cause of high water losses due to wind drift or evaporation,particularly in hot regions. All of the above-mentioned methods consumelarge amounts of energy, and thus there is a need for a system thatconsumes less energy compared to typical high pressure irrigationsystems. The previously used methods further contribute to environmentalproblems, as they are also the primary source of ground watercontamination, since drained water loaded with fertilizers infiltratesthrough soil layers. The field module of the present invention providesa solution to protect ground water from fertilisers and chemicalcontamination, by containing the whole system in a metallic or concretebin, termed as a field module, and keeping the nutrient solution awayfrom soil.

In accordance with the present invention, the proposed field moduledesign (as illustrated in FIG. 1) has a flexibility to be used bothindoors and outdoors. Hydroponic technology, which is a subset ofhydro-culture, is the chosen method for growing plants in thisinvention, using mineral nutrient solution in water, without the need ofsoil. There are many variations of this specific technology, and asspecified, the concept uses a soil-less cultivation method to growturfgrass in a specialty designed setup. The advantages offered byhydroponic technology enable the field module to be extremely versatile,having many uses and applications.

In accordance with an embodiment of the present invention, the fieldmodule 202 comprises a plurality of layers, each encompassing adifferent but relevant function. A first layer comprises a 25 cm deepcontainer 102 which may have a thickness of 23-25 cm. This container ismade of metal, fibreglass, galvanized steel, or constructed usingprefabricated concrete in a full-scale level. This container 102 furtheraccommodates a second layer, which is the horizontal spring layer. Thehorizontal spring layer is made of a 3-4 mm thick perforated corrugatedgalvanized steel sheet 104. These perforated steel sheets 104 have ahorizontal spring—like mechanism, which aids to absorb vertical forcesexerted by external loads, like players, pedestrians or sportingequipment which include, but are not limited to, balls, bats, sticks,etc. These perforated steel sheets 104 further possess a feature ofbeing capable of extending slightly sidewise or moving horizontally froma left position to a right position and vice versa, thus guaranteeingsafety of players and imitating natural resilience of soil. Furthermore,the perforations within the perforated steel sheets 104 assist in fluiddynamics as they allow the flow of water from a downward direction to anupward direction, in addition to allowing plants to extend their rootsto the depth of the container 102, in search for more water andnutrients.

In accordance with another embodiment the present invention, the fieldmodule further comprises a third layer which is a slidable sheet 106made of galvanized steel. The slidable sheet 106 enables the horizontalspring layer to slide above it without corroding the bottom of thecontainer 102. The advantage of this layer is that it can be easilyreplaced once it is exhausted, whilst protecting the container 102. Inaddition the field module also comprises a fourth layer which is a gridlayer 108, made of galvanized steel grid sheet. The purpose of this gridlayer 108 is to carry or hold turf sods and to rest on the horizontalspring layer.

The space above and below the horizontal spring layer is filled withrockwool 112 which acts as a growth substrate. Turf sods 110 are laid onthe top of the grid layer 108, which is then covered with a thin nylonnet. Turf sods 110 are specially grown using a jute pouch stuffed withrockwool 112 to grow turf grass in a strong media where it can serve inthe turf module, yet has a high water holding capacity to accommodateenough water to the roots. All metallic parts of the system arepreferably made of galvanized steel to guarantee durability and costeffectiveness.

In accordance with the present invention, the design of the field modulecomprises an upper grid 108 wherein the turf sods 110 are laid on thetop of the whole field module in a 25 cm deep container 102 equippedwith a horizontal spring-like mechanism made of perforated steel sheets104. The field module comprises of multiple layers, including layers ofrockwool 112, which act as a growth media to quilt the spring mechanismto accommodate the grass roots and to sustain the nutrient solution forits survival. As a smart solution to artificial grass fields, thispresent system has the ability to eliminate the use of potentiallyharmful pesticides and fertilizers, whilst also conserving waterresources. Nonetheless, it is also important for turfgrass facilities todeliver as effective sporting fields to assure performance parameterssuch as efficient movement of sports equipment i.e. bouncing of balls,as well as the safety of players.

The present invention aims to achieve these performance parameters asthe resilience of the field module surface, resulted by the combinationof the spring layer, the water soaked rockwool 112 and turf sods 110,reproduces that of soil based field facilities. As a result of theabove, this system results in a athletic/sports field with an acceptableresilience to prevent player injuries whilst maintaining anenvironmentally sustainable system, imitating the resilience of naturalgrass fields.

In accordance with an embodiment of the present invention, and asdenoted in FIG. 2, there is presented a system layout for receivingnutrient solution from a hydroponic unit, and to circulate and adjustthe circulated water quality. Accordingly, a generic water qualitymanagement unit 206, a geothermal unit 204, and an ultra-violet (UV)unit 208 are main components of the presented system layout whichfacilitates efficient water recycling within the field module 202. Freshwater enriched with nutrients is pumped through a first solenoid valve216, to fill the field module 202. Once the field module 202 is full,first solenoid valve 216 and second solenoid valve 212 remain closed forsome time in order to allow the rockwool to absorb the fresh waterenriched with nutrients. Then, the second solenoid valve 212 opens andthe pump or pressure switch 214 starts to return the used water to theused water tank 210. During the next cycle, the used water is adjustedby the water quality management unit 206 to sustain its pH (Acidity) andElectric Conductivity levels by adding fresh water and/or more nutrientsto be pumped again into the field module 202. Hence, the role of thegeneric water quality management unit 206 is to adjust the water qualityand to further enrich the water with nutrients.

Additionally, the field module 202 is connected with a geothermal unit204, which comprises a heat exchanger (not shown) located 2.5 to 3 meterdeep in the soil in order to warm or cool the water before pumping it tothe field module 202 where the difference between ambient air and deepsoil temperature may reach up to ±10° C., in accordance to day/night orwinter/summer cycle. Thus, as a result of this, the turf will be able totolerate extreme temperatures. Moreover, altering water temperature willallow turf managers to control growth rate of the grass, consequentlyreducing turf cutting costs. The field module 202 further comprises aultra-violet (UV) unit 208 that enables circulated water to bedisinfected in the process. The objective of this UV unit 208 is to killmajority of the germs accumulated in the system from the outdoorenvironment.

In accordance with another embodiment of the present invention, acontrol system (not shown) is utilized to monitor the chemical andphysical properties of water, in addition to its levels or consumption.The controller is programmed to actuate the solenoid valves 212 and 216,to activate flood/drain cycles according to a root zone moistureavailability and the surrounding environment. The control system employsan Arduino microcontroller and a group of compatible sensors.

The present invention provides the parameters necessary for maintainingturfgrass for multiple purposes in dry and hot regions such as UAE andall GCC countries, as the ambient temperature in such areas is too highand as a result, the rate of evaporation increases whilst irrigating.Furthermore, due to the versatility of this system it is applicable asan outdoor turfgrass installation system due to the incorporatedgeothermal unit 204 that will enable the system to function in extremehot or cold environments, as the temperature of the circulated water canbe adjusted to help grass to survive the harsh conditions. Likewise,controlling the water temperature with the geothermal unit 204 in coldenvironments will also preserve grass quality. Furthermore, the proposedfield module 202 aids in controlling grass height in all environments bywater quality and nutrient solution composition, consequently reducingthe use of labour intensive mowers in the fields.

Additionally, due to the nature of this system, the field module canalso be applied to smart cities such as Masdar city in Abu Dhabi, a cityreliant on solar energy and other renewable energy sources, as well asultramodern floating cities, where there is no soil availability andfresh water resources are limited. Operating towards the principles ofsustainable development, such systems also permits green cities to meettheir ‘green’ goals. As a system capable of being used in both indoorand outdoor facilities, it provides many advantages due to itsadaptability. For example, the system can be installed temporarily forshort term events and transported easily to/from different locations. Aswell as its convenience in mobility, the hydroponic field module can beapplied to situations where natural plant cover is usually difficult toattain. For example, on the deck of cruises or on the top of towers,providing travellers or residents natural plant cover instead ofsynthetic cover.

In accordance with another embodiment of the present invention, thehealth hazards posed by indoor contaminants may be problematic and manydifferent factors are contributing to indoor biotic pollution. Soil mayact as a reservoir of fungi and are a source of biological infestation,for this reason, this hydroponic field module can be an alternative,soil-less system used in indoor facilities where biological infestationhas been a prior problem. Similarly, this hydroponic system provides anatural grass solution for children, avoiding health risks imposed bythe plastic artificial turf playgrounds.

It is apparent that the present invention provides an excellent watersaving technique to grow landscape spaces with minimum water, using anutrient solution recycling system. During this efficient process, thissoil-less turfgrass system eliminates soil and ground water pollution.As a sustainable system that works efficiently to save water resources,it also has the capacity to efficiently work under flooding rains, asexcessive water is pumped, ensuring the field is still usable. Underflooding rains, the system still functioning where it can accommodateexcessive water and as a result of this avoid event cancellations orturfgrass damage.

In accordance with a preferable embodiment of the present invention, thedifferent components within the field module have their ownfunctionalities that assist in reducing the ecological impact ofathletic fields and enhance sustainability by reducing water footprint(particularly in the sports industry), in addition to eliminatingsoil/ground water pollution.

In accordance with an embodiment of the present invention, manufacturingand installing the hydroponic turfgrass system is achieved costefficiently, and thus presents few difficulties to fabricate and installin temporary arenas.

Many changes, modifications, variations and other uses and applicationsof the subject invention will become apparent to those skilled in theart after considering this specification and the accompanying drawings,which disclose the preferred embodiments thereof. All such changes,modifications, variations and other uses and applications, which do notdepart from the spirit and scope of the invention, are deemed to becovered by the invention, which is to be limited only by the claimswhich follow.

1. A hydroponic field irrigation system for growing turfgrass, thehydroponic field irrigation system comprising: a field module forgrowing the turfgrass; a used water tank for receiving water from thefield module; an ultra-violet (UV) unit for disinfecting the waterreceived from the used water tank; a water quality management unit foradjusting a quality of the water received from the ultra-violet (UV)unit; a geothermal unit for conditioning a temperature of the waterreceived from the water quality management unit; and a plurality ofsolenoid valves for pumping water into and out of the field module. 2.The hydroponic field irrigation system of claim 1, wherein the pluralityof solenoid valves comprises a first solenoid valve and a secondsolenoid valve.
 3. The hydroponic field irrigation system of claim 2,wherein the first solenoid valve pumps fresh water into the field moduleand the second solenoid valve pumps used water out from the fieldmodule.
 4. The hydroponic field irrigation system of claim 1, whereinthe water quality management unit sustains a pH level and electricconductivity level of the water received from the ultra-violet (UV)unit.
 5. The hydroponic field irrigation system of claim 1, wherein thegeothermal unit functions based on day and night or winter and summercycles for conditioning a temperature of the water received from thewater quality management unit.
 6. The hydroponic field irrigation systemof claim 1, wherein the field module comprises: a horizontal springlayer for absorbing vertical forces exerted by external loads; a steelgrid layer positioned on top of the horizontal spring layer for holdinga plurality of turf sods; and a slidable sheet layer positioned belowthe horizontal spring layer for assisting the horizontal spring layer tomove horizontally.
 7. The hydroponic field irrigation system of claim 6,wherein the field module is a 25 cm deep container made of fiberglass,galvanized steel or concrete.
 8. The hydroponic field irrigation systemof claim 6, wherein the horizontal spring layer is a perforatedcorrugated sheet made of galvanized steel.
 9. A process for growingturfgrass using the hydroponic irrigation system of claim 2, the processcomprising the steps of: pumping out used water from the field module,through the second solenoid valve; storing the used water in the usedwater tank; disinfecting the used water received from the used watertank using ultra-violet (UV) rays; adjusting a pH level and electricconductivity level of the disinfected water, using the water qualitymanagement unit; conditioning the temperature of the water received fromthe water quality management unit, using the geothermal unit; andpumping the conditioned water received from the geothermal unit into thefield module through the first solenoid valve.
 10. The process of claim9, wherein the field module holds a plurality of turf sods on a gridlayer positioned on top of the field module.